<!DOCTYPE html>
<p>There should be a blue square below, and no red.</p>
<div style="-webkit-columns:2; width:100px; -webkit-column-gap:0; background:red;">
    <div id="block" style="height:20px; background:blue;"></div>
    <div>
        <div style="position:relative;">
            <div style="-webkit-column-span:all;"></div>
            <div id="abspos" style="position:absolute;"></div>
            <div></div>
        </div>
    </div>
</div>
<script>
    document.body.offsetTop;
    document.getElementById("block").style.height = "200px";
    document.getElementById("abspos").style.display = "none";
</script>
